1. The Field of the Invention
The present invention relates to drilling equipment and to rock drilling equipment in particular.
2. The Relevant Technology
Many drilling processes are currently known and used. One type of drilling process, referred to as rock drilling, often includes fracturing the rock with a bit to form holes. If desired, explosives can also be placed in the holes and used to break and fracture the rock further. One type of drill used in rock drilling is commonly known as a “drifter.”
Drifters often include a cylindrical drilling mechanism (also known as a drifter cylinder) mounted to a slide frame. The drifter cylinder is often coupled to or includes a drive motor configured to generate percussive and/or rotational forces. The percussive and/or rotational forces are transmitted from the drifter cylinder to a drill bit.
Drifters also often include a feed screw secured to the slide frame and a feed screw nut assembly coupled to the drifter cylinder. The feed screw engages the feed screw nut assembly in such a manner that rotation of the feed screw results in translation of the feed screw nut assembly, and consequently the drifter cylinder, relative to the slide frame. Currently, feed screw nut assemblies often include a front cylinder washer secured to the drifter cylinder. The front cylinder washer provides a housing for a feed screw nut that includes the threads or other features that engage the feed screw. The feed screw nut is often pressed into the front cylinder washer with an interference fit. A feed screw nut further secures the feed screw nut to the front cylinder washer and thus to the drifter cylinder. In such a configuration, as the feed screw rotates, the feed screw nut translates along the relatively stationary feed screw and slide frame.
For example, the drifter cylinder is often advanced relative to the slide frame to move the drill bit into contact with a formation. The feed screw can continue to rotate the drifter cylinder to maintain pressure on the drill bit as the drifter cylinder applies a percussive and/or rotational force to thereby fracture the formation and form a hole therein. Forces between the feed screw and the feed screw nut assembly can cause the feed screw nut to wear over time. This wear can be hastened by the presence of debris and/or grit falling onto the rock drill and into the feed screw nut assembly during drilling operations. Eventually, the feed screw nut assembly can wear out after which it is replaced.
Conventionally, the feed screw nut assembly is replaced by unthreading the feed screw nut from the feed screw nut. Any washers on the feed screw nut are also removed. Thereafter, the feed screw nut is freed from the front cylinder washer by tapping the feed screw nut from the front cylinder washer. A new feed screw nut is then pressed into place in the front cylinder washer and a feed screw nut is then rotated onto the feed screw nut to secure the entire feed screw nut assembly to the front cylinder washer. While such a configuration can provide a replaceable feed screw nut assembly, replacement of the feed screw nut assembly can be time consuming and difficult given the tight space between the feed screw nut assembly and the slide frame. These difficulties can be heightened due to the overall conditions present during rock drilling operations, such as in underground environments.
The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some embodiments described herein may be practiced